The present invention is relating to a semiconductor package, more particularly to a thermally enhanced semiconductor build-up package with a metal carrier.
The chip is trending to small size and high density (having lots of terminals) for CSP (chip scale package) or FC (flip chip) package. Therefore, the intervals between adjacent contacts of die are evolved to become very small, resulting in difficulty of planting the solder balls and causing the problem of surface mounting fail. So that reliability and yield of semiconductor packages would decrease greatly, and the technology of CSP (chip scale package) or FC (flip chip) package is unable to be worked out.
In order to solve the problems mentioned above, a semiconductor package is brought up from U.S. Pat. No. 6,271,469 xe2x80x9cdirect build-up layer on an encapsulated die packagexe2x80x9d. As shown in FIG. 1, the semiconductor build-up package 100 comprises a die 110, an encapsulating material 120 and a plurality of dielectric layers 131 and 132. The die 110 has an active surface 111 forming a plurality of contacts 114. The encapsulating material 120 covers the passive surface 112 and sides 113 of the die 110 for protecting the die 110. The surface of the encapsulating material 120 is coplanar to the active surface 111 of the die 110 for providing a planar area that is necessary for build-up package. The first dielectric layer 131 is formed on the area that is defined by the die 110 and the encapsulating material 120, such as silicon oxide or silicon nitrogen. The first dielectric layer 131 has a plurality of conductive traces 141 that are conductive metals such as copper, aluminum, or alloys thereof. The second dielectric layer 132 is formed above the first dielectric layer 131 and conductive traces 141 and has a plurality of conductive plugs 142. The conductive pads 143 are formed on the second dielectric layer 132. A conductive path is constituted by one of conductive traces 141 and the corresponding conductive columns 142 for electrically connecting the contact 114 of the die 110 with the corresponding conductive pad 143. A solder mask 150 is formed on the second dielectric layer 132. Conductive pads 143 are exposed from the solder mask 150 for planting solder balls 160. Therefore, the contacts 114 of the die 110 may fan out to the conductive pads 143 through the first dielectric layer 131 and the second dielectric layer 132, so that it is easy for planting the solder balls 160 and surface-mounting to PCB (print circuit board), etc. However, due to the die 110 of high density (with a lot of terminals), such as CPU chip, a mass of heat is generated from the die 110, so that the heat-dissipation of the package 100 should be improved. The encapsulating material 120 is made of resin etc, that is not excellent in heat-dissipation, so that the die 110 is easy to damage because overheat causes electromigration.
The main object of the present invention is to provide a semiconductor build-up package. The package comprises a die, a metal carrier and a plurality of dielectric layers. The metal carrier carries the die has a surface for building up a plurality of dielectric layers in order to improve the heat-dissipation of the package.
The secondary object of the present invention is to provide a semiconductor build-up package with vertically conductive columns on the bonding pads of the die. The conductive columns of each dielectric layer, such as copper, aluminum or their alloys, may electrically connect with those conductive columns of adjacent dielectric layer mutually. Some of conductive columns are vertically bonded on the conductive columns of adjacent dielectric layer.
According to the present invention, a semiconductor build-up package comprises a die, a metal carrier and a plurality of dielectric layers. The die has an active surface with bonding pads and a passive surface. The metal carrier has a surface with a cavity for accommodating the die. It is better that the surface of the metal carrier is coplanar to the active surface of the die for providing an area that is necessary to build up a plurality of dielectric layers. The dielectric layers are formed in turn on the area formed by the active surface of the die and the surface of the metal carrier. A plurality of conductive pads are formed on the surface of the dielectric layer of the most upper layer. Each dielectric layer has conductive columns for electrically connecting the corresponding bonding pads of the die with the conductive pads. The conductive columns are made of copper, aluminum or their alloys for providing electrical connection. Further, a plurality of solder balls, bumps or pins are formed on the conductive pads for surface mounting the semiconductor build-up package to a print circuit board, etc. Therefore, a semiconductor package with build-up dielectric layers is especially applied to a semiconductor package with a lot of terminals. By means of conductive traces and conductive columns, the bonding pads of the die fan out to the conductive pads with larger intervals so that it is uneasy to cause the problems of short circuit, etc while the packaging process, planting the solder balls or surface-mounting. Besides, The metal carrier is made of copper, aluminum or other metals with excellent heat-dissipation efficiency and contacts the passive surface and the sides of the die for improved heat dissipation, so the heat generated from die is dissipated fast through the metal carrier for keeping the die from damaging and acting abnormally due to overheat.